A Schlieren imaging system can comprise a digital display configured to provide a background for Schlieren imaging, a cutoff filter onto which the background is focused, and a camera configured to image the cutoff filter and the background to facilitate Schlieren imaging. A calibration method for the Schlieren imaging system can comprise forming a pixel image on a digital display, focusing the pixel image on the cutoff filter, imaging the cutoff filter and the pixel image with a camera; and moving the pixel image with respect to the cutoff filter to align the pixel image with respect to the cutoff filter to facilitate Schlieren imaging. Thus, alignment of the Schlieren imaging system can be substantially simplified.